TUNIS, Tunisia — Tunisia’s prime minister said Sunday a leading suspect in a deadly museum attack on foreign tourists has been killed in anti-terrorist operations, as tens of thousands of Tunisians marched through the capital to denounce extremist violence.

State news agency TAP cites Prime Minister Habib Essid as saying that Khaled Chaieb, also known as Abou Sakhr Lokman, was one of nine terror suspects killed overnight in an operation near the Algerian border.

Chaieb is believed a prominent Algerian militant in al-Qaida’s North African arm, and suspected of leading or helping lead the March 18 attack on the National Bardo Museum.

Twenty-two people, mainly foreigners, and two gunmen were killed in the March 18 attack on the National Bardo Museum.

French President Francois Hollande, Italian Prime Minister Matteo Renzi and several foreign ministers and legislators from other countries are joining an anti-terrorism ceremony in Tunis after the march.

Activists rally in Tunis holding Tunisian flags as they march against the threat of terrorism following the March 18 attack on the Bardo museum.Demotix

The Tunisian government called on all major political parties to join the march from the seat of government at Bab Es-Saadoun to the museum.

Tunisian soldiers stand guard over the march.Getty Images

The international visitors are showing solidarity with Tunisia, whose fragile new democracy was deeply shaken by the museum attack, for which the Islamic State group claimed responsibility.

Tunisian protesters unleashed revolts across the region known as the Arab Spring, and Tunisia is the only country to have built a democratic system as a result.

Interior Ministry spokesman Ali Aroui said Sunday that nine suspected “terrorists” were killed when security forces clashed with the suspects in the southwest region of Sidi Aich, near the Algerian border. He said several extremists were wounded in another clash in the northwest region of Kef, as part of security operations around the country ahead of the march.